Ophthalmic Artery Research Articles

Cerebral Blood Flow Patterns in Patients With Low-Flow Carotid Artery Stenosis, a 4D-PCMRI Assessment.

Compromised cerebral blood flow can contribute to future ischemic events in patients with symptomatic carotid artery disease. However, there is limited knowledge of the effects on cerebral hemodynamics resulting from a reduced internal carotid artery (ICA) blood flow rate (BFR). Investigate how reduced ICA-BFR, relates to BFR in the cerebral arteries. Prospective. Thirty-eight patients, age 72 ± 6 years (11 female). 3-Tesla, four-dimensional phase-contrast magnetic resonance imaging (4D-PCMRI). Patients with ischemic stroke or transient ischemic attack were evaluated regarding the degree of stenosis. 4D-PCMRI was used to measure cerebral BFR in 38 patients with symptomatic carotid stenosis (≥50%). BFR in the cerebral arteries was assessed in two subgroups based on symptomatic ICA-BFR: reduced ICA-flow (<160 mL/minutes) and preserved ICA-flow (≥160 mL/minutes). BFR laterality was defined as a difference in the paired ipsilateral-contralateral arteries. Patients were grouped based on ICA-BFR (reduced vs. preserved). Statistical tests (independent sample t-test/paired t-test) were used to compare groups and hemispheres. Significance was determined at P < 0.05. The degree of stenosis was not significantly different, 80% (95% confidence interval [CI] = 73%-87%) in the reduced ICA-flow vs. 72% (CI = 66%-76%) in the preserved ICA-flow; P = 0.09. In the reduced ICA-flow group, a significantly reduced BFR was found in the ipsilateral middle cerebral artery and anterior cerebral artery (A1), while significantly increased in the contralateral A1. Retrograde BFR was found in the posterior communicating artery and ophthalmic artery. Significant BFR laterality was present in all paired arteries in the reduced ICA-flow group, contrasting the preserved ICA-flow group (P = 0.14-0.93). 4D-PCMRI revealed compromised cerebral BFR due to carotid stenosis, not possible to detect by solely analyzing the degree of stenosis. In patients with reduced ICA-flow, collaterals were not sufficient to maintain symmetrical BFR distribution to the two hemispheres. 2 TECHNICAL EFFICACY: Stage 3.

Soluble epoxide hydrolase gene deletion ameliorates retinal and ophthalmic arterial senescesome

Aims/Purpose: Neurovascular dysfunction in glaucoma is exacerbated by aging. We recently deciphered the crucial role of the cytochrome P450 (CYP) metabolic pathway in the retina (R) and ophthalmic artery (OA). Vasoactive CYP metabolites are hydrolysed by soluble epoxide hydrolase (sEH), thereby diminishing their protective effects. Hence, sEH has emerged as a novel inhibitory target. This study defined the neuro‐vasculoprotective molecular signatures of Ephx2 gene deletion (KO) that impinge senescence in the neural R and OA.Methods: Retinae and OA were isolated from young (3–5 months) and old (12–24 months) male wild type (WT) and KO mice. Samples were pooled (n = 5 mice/group/replicate) to yield 4 biological replicates per group and subjected to label‐free mass spectrometry‐based proteomics and in‐silico bioinformatics analyses.Results: A total of 3706 retinal and 644 OA proteins were identified. Aging profoundly affected the R and OA proteome of WT mice, as demonstrated by the differential expressions of 183 and 111 proteins, respectively. The key changes attributed to age‐related R cellular dysfunction and DNA damage were reflected in the inactivation of NAD+ (p = 9.1 × 10−4) and sirtuin (p = 6.2 × 10−3) signalling pathways. Remarkably, KO had a major influence on the regulation of R proteins involved in bioenergetics reprogramming via mitochondrial homeostasis in young mice, which was shown by the activation of oxidative phosphorylation (p = 1.3 × 10−6) and inhibition of mitochondrial dysfunction (p = 3.4 × 10−3), both of which corresponded to upstream involvement of UQCC3 (p = 7.3 × 10−7). A translation regulator, LARP1, which regulates cell proliferation and protein synthesis, was highly activated in the aged KO retina (p = 10 × 10−16) compared to aged WT (p = 3.1 × 10−5). In the OA, vascular remodelling processes observed in the aged WT mice, primarily compromised microtubule dynamics (3.6 × 10−8) and cell–cell contact (3.7 × 10−6), were significantly attenuated in the KO. Noteworthy, KO significantly mitigated proteome changes attributed to inflammatory response in the OA of both young and aged mice.Conclusions: In gist, the Ephx2 gene deletion significantly ameliorated detrimental senescesome in ocular neurovascular tissues. The potential use of sEH inhibitors for glaucoma needs further investigation.

Are there any indicative signs in colour Doppler imaging of de novo development thyroid orbitopathy after radioiodine treatment

Aims/Purpose: The aim of this study was to identify indicative signs in doppler flow parameters in the central retinal artery (CRA) and ophthalmic artery (OA) which might be associated with de novo development of thyroid‐associated orbitopathy in the early period after radioiodine treatment in patients with Graves disease.Methods: 82 patients with hyperthyroidism were enrolled: 44 with Graves disease and 38 with toxic nodular goitre. In both groups, blood flow parameters in the CRA and OA were analysed before and 2 and 4 weeks after radioiodine administration. The peak systolic velocity (PSV) and end‐diastolic velocity (EDV) were evaluated, and the resistive index (RI) was calculated.Results: There were no statistically significant differences in the PSV, EDV or RI between groups at baseline and 4 weeks after radioiodine administration. Two weeks after radioiodine administration, the RI in the CRA and EDV in the OA were significantly lower, and the EDV in the CRA was higher in patients with Graves disease than in patients with toxic nodular goitre. There was an inverse correlation between baseline thyrotropin receptor autoantibody (TRAb) levels and the difference between the RI at weeks 4 and 2 (RI3‐RI2) in the CRA and a positive correlation between the baseline anti‐thyroid peroxidase antibody concentration and RI3‐RI2 in the OA.Conclusions: Administration of radioiodine results in more prominent features of hyperkinetic circulation. Patients with Graves disease and high TRAb titers have a lower sensitivity to radioiodine treatment. High TRAb titers suggest higher disease activity and a weaker therapeutic effect of radioiodine.

Ophthalmic Artery Morphology and Hemodynamics Associated with White Matter Hyperintensity.

Purpose: To investigate morphological and hemodynamic characteristics of the ophthalmic artery (OA) in patients with white matter hyperintensity (WMH), and the association of the presence and severity of WMH with OA characteristics. Methods: This cross-sectional study included 44 eyes of 25 patients with WMH and 38 eyes of 19 controls. The Fazekas scale was adopted as criteria for evaluating the severity of white matter hyperintensities. The morphological characteristics of the OA were measured on the basis of three-dimensional reconstruction. The hemodynamic parameters of the OA were calculated using computational fluid dynamics simulations. Results: Compared with the control group, the diameter (16.0±0.27 mm vs. 1.71±0.18 mm, P=0.029), median blood flow velocity (0.12 m/s vs. 0.22 m/s, P<0.001), mass flow ratio (2.16% vs. 3.94%, P=0.012) and wall shear stress (2.65 Pa vs. 9.31 Pa, P<0.001) of the OA in patients with WMH were significantly decreased. After adjusting for confounding factors, the diameter, blood flow velocity, wall shear stress, and mass flow ratio of the OA were significantly associated with the presence of WMH. Male sex and high low-density protein level were associated with moderate-to-severe total WMH, and smoking was associated with the moderate-to-severe periventricular WMH. Conclusions: The diameter, blood flow velocity, mass flow ratio, and wall shear stress of the OA were independently associated with the presence of WMH. Atherosclerosis might be involved in the common mechanism of the occurrence of WMH and the OA changes.

Endovascular Treatments for Aneurysms Involving a Major Branch.

Remarkable advances have been made in the endovascular treatment of intracranial cerebral aneurysms. These advances include various adjunctive techniques, increased indications for endovascular treatment, and improved treatment results. Furthermore, the number of cerebral aneurysm treatments using flow diverters (FDs) is expected to increase. However, the reported long-term rate of branch artery occlusion after FD treatment has been reported is 15.8%. Moreover, the complete aneurysm obliteration rate is low if normal branches arise from an aneurysm neck or dome. Flow diverter placement for ophthalmic artery, posterior communicating artery, and anterior choroidal artery aneurysms is often difficult because these normal branches often arise from the aneurysm neck or dome. Therefore, in many cases, coil embolization, which can occlude the aneurysm while preserving branch vessels, should be selected. Although not yet established, various adjunctive techniques and other endovascular treatments that can be performed safely have been reported. Treatment must be planned after understanding the advantages and disadvantages of each treatment method.

The effects of cardiac stenting on the organ of vision in patients with chronic ischemic optic neuropathy

Purpose. To evaluate the effect of coronary artery stenting on the functional state of organ of vision in patients with chronic ischemic optic neuropathy (CION). Material and methods. 33 patients (53 eyes) diagnosed with CION aged 51 to 85 years, average 66.78±1.54 years, who underwent stenting of the coronary arteries. Results. Stenting of the coronary arteries did not affect on BCVA parameters, the percentage of pupil contraction increased from 9.57±0.49 to 9.74±0.46 ms (p&lt;0.05), the recovery of the sympathetic phase of the pupil’s reaction to light accelerated from 83.79±0.44 to 83.56±0.43 ms (p&lt;0.05), a decrease in IACG was recorded from 13.39±4.67 to 7.01±0.56 mm Hg. Art./ mm3 (p&lt;0.05), negative dynamics of CFSM in green color from 33.5±0.8 to 33.06±0.73 after 1 month and to 33.17±0.75 after 3 months from initial values, deterioration of static perimetry after 3 months from 94.60±0.97 to 93.17±1.88 (p&lt;0.05), narrowing of kinetic perimetry to green stimulus after 1 month from 267.48±13.96 up to 267.48±13.96 gr. (p&lt;0.05). Conclusion. In the subjects, cardiac symptoms predominated rather than visual ones. In patients who underwent stenting of the coronary arteries, BCVA did not change and remained at the same level throughout the entire observation period; according to ultrasonography of the orbital vessels, there was an insignificant redistribution of blood flow in the ophthalmic artery basin; IACG significantly decreased by 2 times after 1 month (p&lt;0.05), the indicator of CFSM for green color worsened in long-term follow-up (p&lt;0.05), negative dynamics were recorded according to the program of static perimetry and kinetic perimetry for green color 1 later (p&lt;0.05). Revascularization of the coronary arteries affects the restoration of the sympathetic phase of the pupil’s response to light and the force of pupil contraction (p&lt;0.05). Key words:: chronic ischemic optic neuropathy, the cardiovascular system, cardiac stenting, optic nerve

Radiological evaluation of middle meningeal artery by 3D rotational angiography.

This study aimed to evaluate the topographic features and branches of the middle meningeal artery (MMA) by three-dimensional rotational angiography (3DRA) and describe its variations' radiological classification based on previous clinical examples of cadaver studies and literature. We consecutively evaluated 87 cerebral hemispheres, including 32 females and 49 right sides between May 2020 and December 2021 who had undergone unilateral or bilateral cerebral and carotid artery 3D rotational angiography imaging by CCA injection and between 18 and 76-years-old. Maximum intensity projection images with 10-30 mm slice thickness were used for the morphological evaluations and measurements of MMA and its foramen, canal, and branches. The diameters of the common carotid artery, internal carotid artery, and external carotid artery were significantly smaller in females than in men (p = 0.021, 0.021, and <0.001, respectively). According to the branching pattern, the most common pattern of the MMA was Type Ia (49.4%). The ophthalmic artery completely originated from MMA in the 1 (1.1%) cerebral hemisphere. The MMA arises from the ophthalmic artery in 2 cerebral hemispheres (2.3%), and the ophthalmic artery and maxillary artery in 2 cerebral hemispheres (2.3%). It was observed that the branching pattern may show differences when compared to the cadaver studies with a radiologic evaluation with 3D-RA.

Ocular Ischemic Syndrome in the Setting of Normal Carotid Duplex Ultrasound

Purpose: To describe two cases of ocular ischemic syndrome (OIS) that were initially ruled out due to a negative carotid duplex ultrasound (DUS) but eventually confirmed by angiography studies. Methods: Case series. Results: Case 1: A 67-year-old female presented with symptoms suggestive of OIS, but carotid DUS was negative, and the patient was diagnosed with occlusive retinal vasculitis due to retinal non-perfusion and vascular leakage on fluorescein angiography (FA). Immunosuppressive therapy was initiated but her symptoms did not improve. Computerized tomography angiography (CTA) was significant for severe osteal stenosis of the aortic arch vessels. Left common carotid angioplasty and stenting resulted in complete resolution of the symptoms and vascular leakage of the left eye. Case 2: A 41-year-old male with cryoglobulinemia-associated vasculitis complained of symptoms consistent with OIS, which was initially ruled out through a negative carotid DUS. FA revealed delayed arterial filling with poor retinal perfusion. Magnetic resonance angiography (MRA) revealed ophthalmic artery stenosis which was attributed to the underlying systemic vasculitis. Conclusion: CTA or MRA should be performed to rule out OIS if DUS is negative in the setting of high clinical suspicion. Carotid ostial and ophthalmic artery stenoses are rare but possible causes of OIS.

Proteome landscape and interactome of voltage-gated potassium channel 1.6 (Kv1.6) of the murine ophthalmic artery and neuroretina

The voltage-gated potassium channel 1.6 (Kv1.6) plays a vital role in ocular neurovascular beds and exerts its modulatory functions via interaction with other proteins. However, the interactome and their potential roles remain unknown. Here, the global proteome landscape of the ophthalmic artery (OA) and neuroretina was mapped, followed by the determination of Kv1.6 interactome and validation of its functionality and cellular localization. Microfluorimetric analysis of intracellular [K+] and Western blot validated the native functionality and cellular expression of the recombinant Kv1.6 channel protein. A total of 54, 9 and 28 Kv1.6-interacting proteins were identified in the mouse OA and, retina of mouse and rat, respectively. The Kv1.6-protein partners in the OA, namely actin cytoplasmic 2, alpha-2-macroglobulin and apolipoprotein A-I, were implicated in the maintenance of blood vessel integrity by regulating integrin-mediated adhesion to extracellular matrix and Ca2+ flux. Many retinal protein interactors, particularly the ADP/ATP translocase 2 and cytoskeleton protein tubulin, were involved in endoplasmic reticulum stress response and cell viability. Three common interactors were found in all samples comprising heat shock cognate 71 kDa protein, Ig heavy constant gamma 1 and Kv1.6 channel. This foremost in-depth investigation enriched and identified the elusive Kv1.6 channel and, elucidated its complex interactome.

Ophthalmic artery reversal predicts contralateral body weakness symptoms better than carotid Doppler velocity-preliminary results.

The measurement of blood velocity in the carotid artery has been the most popular noninvasive method of identifying and classifying carotid stenosis for half a century. Carotid stenosis is an indicator of elevated risk of stroke; anatomic revascularization reduces the chance of stroke by more than half. Controversy persists on how patients with severe carotid stenosis should be selected for anatomic revascularization. Patients with a connected circle of Willis (coW) might not benefit from anatomic revascularization; patients with two segments missing in the coW are most likely to benefit from revascularization. Based on this analysis of data from carotid duplex examinations and transcranial Doppler examinations including ophthalmic artery (OA) direction in 28 patients, a refined carotid examination protocol is proposed. This refinement includes Doppler measurement of OA flow direction and documentation of internal carotid artery (ICA) bruit in addition to the adoption of an ICA peak systolic velocity (PSV) criterion exceeding 350 cm/s for identification of the patient most likely to benefit from carotid stenosis treatment. Sensitivity and specificity of OA direction or carotid bruit are 84.6%±5.4%, 71.4%±2.1% and for PSV >350 cm/s are 84.6%±5.4%, 59.5%±2.3% for predicting contralateral body weakness. The proposed examination can be performed with the same duplex scanner and scan head currently used for carotid examinations with little additional time.

Smaller optic nerve diameters and reduced flow velocity of ophthalmic artery suggest a history of optic neuritides: Transorbital Ultrasonography and Doppler Ultrasound in multiple sclerosis

Smaller optic nerve diameters and reduced flow velocity of ophthalmic artery suggest a history of optic neuritides: Transorbital Ultrasonography and Doppler Ultrasound in multiple sclerosis

Angiographic characteristics and treatment approach in patients undergoing intra-arterial chemotherapy for retinoblastoma.

To identify the specific clinical and angiographic variables that determine the success of intra-arterial chemotherapy (IAC) in a patient with retinoblastoma. Medical records from patients undergoing intra-arterial chemotherapy for the treatment of retinoblastoma between January 2015 and June 2020 within a large academic ocular oncology practice were retrospectively reviewed. Demographics were recorded together with clinical, ocular, and angiographic variables such as the diameter of the ophthalmic artery (OA), angle of ophthalmic artery takeoff, and branching pattern of ophthalmic vasculature. Forty-four eyes from 33 patients with retinoblastoma treated with IAC were identified. Over the total 32 mean months of follow-up, these patients received 144 total catheterizations and a mean of 3.2 IAC cycles for each eye. The number of IAC cycles and the chemotherapeutic agent used did not vary significantly with worsening International Classification of Retinoblastoma (ICRB) groups (P > 0.1). Cumulative dose did not vary with the ICRB group for eyes treated with melphalan, topotecan, or carboplatin (P > 0.1). A higher ICRB group was associated with a smaller mean ophthalmic artery diameter across all procedures (P = 0.016), and femoral artery diameter did not vary significantly between ICRB groups (P = 0.906). A higher cumulative dose of IAC was significantly associated with a smaller takeoff angle of the OA (melphalan, P = 0.011; topotecan, P = 0.009; carboplatin, P = 0.031) in patients who underwent successful IAC procedures. Ophthalmic artery diameter and femoral artery diameter did not have a significant association (P > 0.1) with higher IAC doses in successful IACs. Cumulative IAC dose was not significantly associated with ophthalmic vasculature branching pattern, presence of choroidal blush, temporary OA vasospasm reported during the procedure, and OA occlusion upon microcatheter placement. In this study, neurosurgical angioanatomy appeared to influence the cumulative dose of chemotherapy needed during IAC for retinoblastoma. In the future, these anatomic variables may be used to guide the frequency of monitoring, dosing, and estimation of recurrence risk.

Persistent trigeminal artery variant and presumed ophthalmic artery simultaneously arising from the inferolateral trunk incidentally diagnosed by magnetic resonance angiography.

To describe a case of persistent trigeminal artery variant (PTAV) and presumed ophthalmic artery (OA) simultaneously arising from the inferolateral trunk (ILT). A 53-year-old woman with an initial episode of convulsion underwent cranial magnetic resonance imaging (MRI) and MR angiography (MRA) of the intracranial region for the evaluation of brain and vascular lesions. The MR machine was a 3-T scanner. MRI revealed no pathological brain lesions. On MRA, the left anterior inferior cerebellar artery (AICA) arose from the cavernous segment of the internal carotid artery (ICA), indicative of the PTAV. The arising point was more distal than the usual point, and the presumed OA also arose simultaneously from the short common trunk, which was considered the ILT. There are two types of PTA: lateral (usual) and medial (intrasellar) PTA. The lateral-type PTA and PTAV arise from the ICA of the distal precavernous-proximal cavernous segment and take a course similar to that of the posterior fossa. The medial type arises slightly more in the distal cavernous segment than in the lateral type. The OA rarely arises from the cavernous segment of the ICA and enters the orbit via the superior orbital fissure. The origin of this type of OA is considered to be the ILT. We herein report a case of a PTAV and presumed OA arising simultaneously from an ILT. No similar case has been reported in the relevant English language literature.

High-fat diet causes endothelial dysfunction in the mouse ophthalmic artery

Obesity is a significant health concern that leads to impaired vascular function and subsequent abnormalities in various organs. The impact of obesity on ocular blood vessels, however, remains largely unclear. In this study, we examined the hypothesis that obesity induced by high-fat diet produces vascular endothelial dysfunction in the ophthalmic artery. Mice were subjected to a high-fat diet for 20 weeks, while age-matched controls were maintained on a standard diet. Reactivity of isolated ophthalmic artery segments was assessed in vitro. Reactive oxygen species (ROS) were quantified in cryosections by dihydroethidium (DHE) staining. Redox gene expression was determined in ophthalmic artery explants by real-time PCR. Furthermore, the expression of nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2), the receptor for advanced glycation end products (RAGE), and of the lectin-like oxidized low-density-lipoprotein receptor-1 (LOX-1) was determined in cryosections using immunofluorescence microscopy. Ophthalmic artery segments from mice on a high-fat diet exhibited impaired vasodilation responses to the endothelium-dependent vasodilator acetylcholine, while endothelium-independent responses to nitroprusside remained preserved. DHE staining intensity in the vascular wall was notably stronger in mice on a high-fat diet. Messenger RNA expression for NOX2 was elevated in the ophthalmic artery of mice subjected to high fat diet. Likewise, immunostainings revealed increased expression of NOX2 and of RAGE, but not of LOX-1. These findings suggest that a high-fat diet triggers endothelial dysfunction by inducing oxidative stress in the ophthalmic artery via involvement of RAGE and NOX2.

Bilateral infraoptic origin of the anterior cerebral artery: illustrative case.

A bilateral infraoptic origin of the anterior cerebral arteries (ACAs) is a rare anatomical variant that can be encountered during anterior skull base surgery. The ACAs arise from the internal carotid artery (ICA) at the level of the ophthalmic artery and course medially, traveling inferior to the ipsilateral optic nerves. Herein, the authors discuss the different configurations of the anatomical variant, its prevalence, and hypotheses leading to the variable configuration of this anomaly. A 67-year-old woman presented with worsening dizziness over a week-long period and was found to have a large left sphenocavernous meningioma with optic, cavernous, and suprasellar extension. The tumor incorporated the left supraclinoid ICA and its branches. She underwent a left modified orbitozygomatic craniotomy for tumor resection. Early identification of the aberrant ACA anatomy was crucial in avoiding vascular injury. While this variant is typically encountered during the treatment of vascular pathologies-namely, intracranial aneurysms-its existence should be kept in mind during the treatment of any anterior skull base pathology. Failure to account for the presence of this variant may lead to potential intraoperative complications.

Prediction of adverse outcome by ophthalmic artery Doppler and angiogenic markers in pregnancies with new onset hypertension

ObjectivesTo compare the ophthalmic artery Doppler peak systolic velocity ratio (OA PSV-ratio) and soluble fms-like tyrosine kinase-1/placental growth factor ratio (sFlt-1/PlGF ratio) in predicting adverse maternal and perinatal outcomes in women presenting with new onset hypertension. Study designProspective cohort study in a specialist hypertension clinic, within a tertiary referral centre. Main outcome measuresComparison between the OA PSV-ratio and sFlt-1/PlGF ratio in predicting delivery within one week from presentation and adverse maternal and perinatal outcomes e.g. severe hypertension, neonatal unit admission, small for gestational age. ResultsWomen who delivered within one week, compared to those who did not, had a higher OA PSV-ratio (0.82 vs 0.71, p < 0.01) and sFlt-1/PlGF ratio (93.3 vs 40.5, p = 0.08). Independent predictors of the OA PSV-ratio included mean arterial pressure and maternal weight and predictors of the sFlt-1/PlGF ratio included diastolic blood pressure and use of antihypertensive medications. Prediction of adverse outcomes with both ratios were similar and only modest e.g. AUROC for predicting delivery within one week for OA PSV-ratio was 0.57 (95% CI 0.47–0.67) and for sFlt-1/PlGF ratio was 0.61 (95% CI 0.52–0.70) (p = 0.53). ConclusionsIn women presenting with new onset hypertension, the OA PSV-ratio and sFlt-1/PlGF ratio have similar and modest performance in predicting adverse outcomes.

Optic Canal Size is an Indicator for the Accessory Optic Canal: Applications for Anterior Clinoidectomy

BackgroundThe ophthalmic artery normally travels with the optic nerve through the optic canal. However, sometimes, the ophthalmic artery travels through a foramen within the optic strut named an accessory optic canal, double optic canal, or ophthalmic canal. This variant puts individuals at an increased risk for blindness or death during anterior clinoidectomy due to unforeseen hemorrhage of the ophthalmic artery or internal carotid artery when the optic strut is separated from the body of the sphenoid bone. Several features make the accessory optic canal difficult to recognize on imaging: its variant nature, small size, and ability to masquerade as a caroticoclinoid foramen or a pneumatized sphenoidal structure. Hence, improved methods of presurgical identification are warranted. The aim of this study was to assess the size and shape of the optic canal, with and without a concomitant accessory optic canal, to determine whether measurement of the optic canal may provide useful information regarding the presence of an accessory optic canal. MethodsIn 191 dry crania, optic canals with and without concomitant accessory optic canals were assessed for the following parameters: canal area, canal perimeter, circularity, solidity, the axes and aspect ratio of a best fit ellipse, and roundness. ResultsNormal optic canals were found to have a larger area (p=0.036), perimeter (p=0.043), and minor axis of a best fit ellipse (p=0.031) than the optic canals that occurred alongside accessory optic canals. ConclusionsAsymmetry in optic canal size can help indicate the presence of a unilateral accessory optic canal prior to surgery.

Abstract 177: Clinical and Imaging Outcomes of Ophthalmic Aneurysm Flow Diversion with or without Adjunctive Coiling

Introduction Flow diversion (FD) is commonly used for the treatment of aneurysms involving the ophthalmic segment of the carotid artery (COA). The origin of the ophthalmic artery (OA) in relation to the aneurysm sac can affect recurrence and complications. We studied the effects of COA treatment with FD alone or in combination with coil embolization, based on the origin of the ophthalmic artery in‐relation to the aneurysm sac. Methods Retrospective analysis of a prospectively collected tertiary center database. Based on the ophthalmic artery origin, four types of carotid ophthalmic aneurysms were previously described and implemented in this study: OA originates from Type A. directly from the aneurysm fundus, B. aneurysm neck, C. inner curve of the carotid siphon, and D. OA separate from the aneurysm. Imaging outcomes were aneurysm occlusion and OA patency at 1‐year, determined by Digital Subtraction Angiography (DSA) or MRA. Clinical outcome was treatment‐related visual complications. Results A total of 60 patients treated at our tertiary center between January 2017 and November 2019 were reviewed. 4 patients were lost to follow up. Clinical and angiographic data of 59 COAs treated with FD +/‐ coil embolization were available. FD alone was used in 44 (75%) aneurysms, the rest had adjunct coiling. Median age was 55. Ten (17%) patients were men. Thirty two aneurysms (55%) were Type D, 22 (37%) Type B, 5 (8%) Type A. No Type C aneurysms were identified. Overall complete occlusion rate was 82%; 94% vs 71% for adjunct coiling vs FD only, respectively. Residual filling was seen in 4 (12%) Type D aneurysms, 8 (35%) Type B aneurysms, and 1 (20%) Type A aneurysm. The ophthalmic artery was occluded at follow up in all but one patient in Type A aneurysm group (80%), 2 (7.1%) in Type D, and 6 (27%) in Type B. 6/15 (40%) of patients in the adjunct coiling group had transient and short‐lasting disturbing visual symptoms, vs 7/44 (16%) in the FD only group. No patient had long‐term visual complications. A total of 10 patients showed OA occlusion at follow up, 4 of them in the adjunct coiling group (26%). There was 1 patient (2%) with a non‐disabling stroke due to antiplatelet therapy interruption and in‐stent thrombosis. Conclusion Flow diversion appears safe and effective for COA treatment. Adjunct coil embolization increased COA occlusion 1 year after FD treatment without significant increase in long‐term visual complications. Adjunct coiling and ophthalmic artery origin location appear to have a significant effect on treatment result, and should be considered at treatment planning.

Abstract 118: Ophtalmic‐ethmoidal dural arteriovenous fistula

Introduction Ophtalmic dural arteriovenous fistula is not a common diagnosis. They usually present as subarachnoid hemorrhage, or parenquimatous hemorrhage as in our patient. Male, 46 years old, electric worker, right‐handed. Family: Diabetes mellitus, gastric cancer, COVID. Tobacco, Marihuana and alcohol positive. Presents SAH on October 2022 posterior to physical activity. Intense cephalea, nausea and vomit, anxiety, with no neurological deficit, and went to sleep. Two days after, he presents somnolence, altered verbal speech, and disorientation, and next day he presents seizure, then he goes to emergency. Physical examination: Normal. Neurological examination: Disorientation, confused and non‐fluent language, altered mental status. No other signs of focalization. No visual affectation. Methods Patient was evaluated at emergency room. CT: SAH and parenquimatous left frontal basal hemorrhage of 2x3.4cm. AngioCT: a dilated orbito frontal vein, and a venous aneurysm at the anterior third of the superior sagittal sinus. Fronto basal fistula was suspected. Angiography was performed, and it was found right fronto‐basal arteriovenous fistula Borden III, Cognard IV. Comunication between righ ophthalmic artery to superior sagittal sinus. Patient was delivered home three days after the event. When patient had recovered clinically, we performed embolization. Results We performed doble access, femoral artery and braquial vein. It was not possible to achieve to the fistula through vein system. We catheterized ophthalmic artery, and did embolization through it, with a successful result, and with no ophthalmic symptoms after embolization. Conclusion Dural arteriovenous fistulas are shunts found from dural vessels. This type of fistulas ophthalmic‐ethmoidal are rare. We performed angiography which is the know gold standard for diagnosis, and we tried to do a combined access which was not possible, so we performed simple embolization through ophthalmic artery. This approach it is performed and it has been reported as an effective and safe treatment.

Abstract 093: Carotid Stump Syndrome: an Insidious Source of Recurrent Ischemic Strokes

Introduction Carotid stump syndrome (CSS) is a paradoxical phenomenon that occurs when there are repeated ischemic events in the carotid vascular territory despite demonstrated occlusion of the ipsilateral internal carotid artery (ICA). It is thought to be caused by turbulent blood flow in the patent stump of the occluded ICA creating microemboli which reach the brain through anastomotic channels and retrograde flow. We present a case of recurrent infarctions in setting of known ipsilateral ICA occlusion, who was diagnosed with carotid stump syndrome. Methods A male veteran in his 60s with a medical history of DVTs on apixaban, PVD, and ischemic stroke with residual right‐sided weakness, presented with worsening right‐sided weakness and difficulty with ambulation. Two months prior to the presentation he was diagnosed with acute infarcts in left frontal, parietal, and temporal lobes due to thromboembolism from left ICA occlusion. On presentation his neurological exam revealed right‐sided hemiparesis. MRI brain showed multiple acute and chronic cortical and subcortical infarcts in the left frontotemporoparietal lobes and lack of flow void in the left distal ICA. To further evaluate the dynamics of blood flow patient underwent a cerebral angiogram which confirmed the diagnosis of complete occlusion of left ICA and demonstrated reconstitution of the intracranial ICA through retrograde filling via the ophthalmic artery and anastomotic branches with the internal maxillary artery (IMax). For secondary prevention he was started on statin and aspirin while his home Apixaban was continued. Surgical and endovascular treatment approaches were discussed but the patient declined any intervention. In his four months follow up clinic visit he had no further concerns of recurrent strokes or new symptoms. Results Carotid stump syndrome is a rare cause of cerebral and retinal ischemia; however, it must be considered in patients with recurrent ischemic strokes and chronic ipsilateral ICA occlusion. Due to the patent proximal, or perhaps in some cases distal, carotid stump, there’s turbulent flow and hence the thrombus formation can occur. Hemodynamic and embolic factors attribute towards the microembolization from the proximal carotid stump through the external carotid artery (ECA), into the facial artery and IMax and their distal branches which anastomose with the ophthalmic artery, causing the emboli to end up in the major branches of the carotid terminus. If a distal stump is symptomatic, then the microemboli can readily end up in the distal ICA branches. In addition to medical management with DAPT or anticoagulation and high intensity statin, our literature review supports endovascular or surgical interventions due to reportedly good outcomes. Interventional approaches may include ECA‐ICA stenting with a covered stent or stent‐assisted coil embolization of the proximal stump. Surgical procedures include an endarterectomy on the ipsilateral ECA or contralateral ICA to increase collateral circulation. ECA‐ICA bypass is another option. Conclusion Carotid stump syndrome is a rare and underrecognized cause of recurrent ischemic strokes, though it is a potentially treatable entity. The therapeutic goals include medical management along with endovascular or surgical treatment whenever possible.